[PATCH v3 3/4] x86: limit issuing of IBPB during context switch

2023-01-25 Thread Jan Beulich
When the outgoing vCPU had IBPB issued upon entering Xen there's no need for a 2nd barrier during context switch. Signed-off-by: Jan Beulich --- v3: Fold into series. --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -2015,7 +2015,8 @@ void context_switch(struct vcpu *prev, s

Re: [PATCH v3 3/4] x86: limit issuing of IBPB during context switch

2023-01-26 Thread Andrew Cooper
On 25/01/2023 3:26 pm, Jan Beulich wrote: > When the outgoing vCPU had IBPB issued upon entering Xen there's no > need for a 2nd barrier during context switch. > > Signed-off-by: Jan Beulich > --- > v3: Fold into series. > > --- a/xen/arch/x86/domain.c > +++ b/xen/arch/x86/domain.c > @@ -2015,7 +2

Re: [PATCH v3 3/4] x86: limit issuing of IBPB during context switch

2023-01-26 Thread Jan Beulich
On 26.01.2023 21:49, Andrew Cooper wrote: > On 25/01/2023 3:26 pm, Jan Beulich wrote: >> --- a/xen/arch/x86/domain.c >> +++ b/xen/arch/x86/domain.c >> @@ -2015,7 +2015,8 @@ void context_switch(struct vcpu *prev, s >> >> ctxt_switch_levelling(next); >> >> -if ( opt_ibpb_ctxt_swi

Re: [PATCH v3 3/4] x86: limit issuing of IBPB during context switch

2023-01-27 Thread Andrew Cooper
On 27/01/2023 7:51 am, Jan Beulich wrote: > On 26.01.2023 21:49, Andrew Cooper wrote: >> On 25/01/2023 3:26 pm, Jan Beulich wrote: >>> --- a/xen/arch/x86/domain.c >>> +++ b/xen/arch/x86/domain.c >>> @@ -2015,7 +2015,8 @@ void context_switch(struct vcpu *prev, s >>> >>> ctxt_switch_levell

Re: [PATCH v3 3/4] x86: limit issuing of IBPB during context switch

2023-02-06 Thread Jan Beulich
On 27.01.2023 18:47, Andrew Cooper wrote: > On 27/01/2023 7:51 am, Jan Beulich wrote: >> On 26.01.2023 21:49, Andrew Cooper wrote: >>> On 25/01/2023 3:26 pm, Jan Beulich wrote: --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -2015,7 +2015,8 @@ void context_switch(struct vc